Process and apparatus for quenching heat treated articles



Aug. 30, 1932. G. A. JOHNSON 1,874,300

PROCESS AND APPARATUS FOR QUENCHING HEAT TREATED ARTICLES Filed Jan. 9, 1929 Patented Aug. 30, 1932 UNITED ,sTATEs PATENT OFFICE GEORGE. JOHNSON, OF CHICAGO, ILLINOIS, ASSI GNOR TO W. H. MINER, INC., 01' CHI- CAGCyILLINOIS, A CORPORATION OF DELAWABE raocnss mn ATTARATUs roe ounncnme HEAT TREATED AnTIcLns Application filed January 9, 1929. Serial No. 331,316.

This invention relates to process and apparatus for quenching heat treated articles.

In the manufacture ofcast,;rolled or forged metal articles, it is important that the quench- 5 ing bath in which the articles, while in highly heated condition, are immersed for hardening or tempering purposes, is maintained at the required uniformly low temperature, so that the minimum amount .of time will be consumed in performing this operation. In the usual form of quenching tank now generally employed for this purpose, the cooling fluid is admitted through an intake at the bottom of the tank and drawn off through a pipe drain near the top. Such arrangements have been found to'be ineflicient because the heated fluid adjacent thepipe drain only is drawn off, leaving hot fluid in the upper part of the tank remote from the drain, which mixes with the incoming cooler fluid, thereby raising the temperature of the entire bath to a marked degree, thus renderingthe same inefficient. Further, the usual pipe drain at the top of the tank, in addition to withdrawing only the hot fluid directly adjacent thereto, also effects an upward current adjacent the drain, thereby withdrawing a considerable portion of, the cooler fluid fromthe lower level.

It is the principal object ofmy. invention to overcome the defects pointed out by providing a cooling-bath to which the cooling fluid is constantly fed and c'onstantlyskimming off the entire upper surfaceportion of the bath, thus effectively removing the most highly whereby the heatedupperportion of the fluid is skimmed off.

A still further object of the invention is to provide a process of quenching cylindrical articles closedat one end, by immersing the same in inverted condition in a quenching tank, from the top of which the heated fluid is skimmed OE, and feeding the cooling fluid to the bottom of the tank inv a continuous heated portion of the fluid and maintaining the bath at substantially the required umstream and directingthe same upwardly with- V l in the cylinder.

Another object of the invention is to provide a process of quenching cylindrical metal articles closed at one end, by immersing the same in inverted condition in a cooling bath to which a cooling fluid is constantly fed, directing the cooling fluid into the cylinder through the open bottom end thereof, wherein the cylinder is vented at the upper end to allow free circulation of the cooling fluid therethrough. V q

Other and further objects of the invention will more clearly appear from the description and claims hereinafter following. In the drawing, forming a part of this specification, Figure 1 is a longitudinal, vertical,

sectional view of a quenching tank,showing m y improvements in connection therewith and illustrating my improved quenching process. Figure 2-is a top plan view of the tank shown in Figure 1. And Figure 3 is a transverse, vertical, sectional view, corre sponding substantially to the line 3-3 of Figure 1. V V

Referring first to my improved apparatus, the same preferably comprises a substantially rectangular tank having longitudinally extending, spaced, vertical side walls 10-10, transverse vertical end walls 11-11, and a horizontal bottomwall 12. The tank is divided into two compartments by a transverse partition wall 13 which, as most clearly shown in Figure 1, is of lesser height than the side and end walls of the tank, thereby providing a dam between the two compartments, over which the cooling fluid may flow. The transverse wall 13 is located nearer one end of the tank than the other, thereby providing a relatively small compartment at the "able manner to the bottom wall 12 of the tank.

As herein shown, the drain-pipe 14 is secured by a pipe flange member 15 which is fixed to theouter face of the bottom wall 12 of the tank. The upper end of the drain-pipe 14 is preferably flush with the inner surface of the LII bottom wall 12 so that the fluid will be effectively drained from the smaller compartment of the quenching tank.

The relatively larger compartment of the tank serves to contain the fluid which forms the quenching bath. As shown in Figure 1, the normal level of the fluid in this compartment is even with the top edge of the wall 13 which forms the dam, as shownin dotted lines in said figure. The cooling fluid is fed to the bath by means of an inlet feed-pipe 16 which extends through the'bottom wall 12 and projects a considerable distance into the larger compartment, as shown in Figures 1 and 3.

The feed-pipe 16 may be secured to the bottom wall 12 in any suitable manner and, as herein shown, is fixed thereto by a flange member 17. The feed-pipe 16 is closed at the upper end by a cap 18 and the side wall is provided with a plurality of perforations 19-19 through which the fluid is ejected into the bath.

When metal articles of special formation are quenched in the bath, especially cylindrical castings which are open at one end, a combined supporting member and carrier 20 is preferably employed as shown in the drawmg, but when ordinary'articles which are not hollow are quenched, no special holding means is necessary and the same may be immersed directly in the both. In carrying out the process of quenching metal articles in the bath, the larger compartment is filled by means of the feed-pipe 16 through which the cooling fluid is constantly fed. As will be evident, due to the constant'feed of the fluid, the level in the larger compartment will be raised until the fluid at the top of the bath flows over the dam 13 into the smaller compartment. Inasmuch as the feed of the cooling fluid is continuous,.the flow over the dam will also be continuous. The fluid which enters the smaller compartment is drained therefrom through the pipe 14. As will be evident, when a highly heated metal article is immersed in the bath, the fluid in cooling the same will become heated and rise to the top. Inasmuch as the fluid flows over the dam 13, the most highly heated portion of the same at the top of the bath will be skimmed off in the form of a sheet, thereby leaving the cooler fluid in the larger compartment of the tank. The temperature of the fluid of the bath below the upper surface thereof will thus be maintained at a substantially uniform relatively low temperature.

While my improved apparatus and process are adapted for use in connection with various kinds of metal articles, the same are especially adapted for use in connection with steel castings which are quenched after being cast and while still in a highly heated condition, thereby tempering and hardening the same.-

As hereinbefore mentioned, the special sup from the interior of the cylinder.

The combined support and carrier comprises a pair of side members 23-23 and end members 2424, the side members 23 being disposed in parallel relation at the lower end of the member 20 and diverging upwardly at the top of said member. The end members 24 are similarly formed, thereby providing a carrier and support having a flaring mouth portion at the upper end so that the cylinder may be properly guided into the bottom sup porting portion and centered on the member 20. Adjacent the bottom end, the member 20 is provided with a horizontal inwardly projecting flange :25 on each wall thereof, the

flanges 25 being spaced from the bottom of the tank as shown in Figures 1 and 3. Two transversely disposed, spaced supporting strips or rods 2626 are secured to opposed flanges 25 and span the opening between said flanges.

As shown in the drawing, the side and end walls 23 and 24 are vertically slotted, thereby providing'a basket-like structure to permit the free circulation of the cooling fluid therethrough. A. pair of transversely disposed angle bars 2727 are secured to the side members 23 at the top of the combined support and carrier 20. These angle bars are of such a length as to overlap the top edges of the side walls 10 of the quenching tank. These bars serve as handle members to permit lowering the carrier 20 into the bath and removing the same therefrom. When a. cylindrical member, of the type shown in the drawings, is to be quenched in the bath, the same is inserted within the member 20 in the inverted position shown in the drawing and the combined supporting member and carrier lowered into the tank in such a position that the feed-pipe 16 will pass between the supporting rods or strips 26 into the cylinder. The height of the pipe 16, as shown in Figure 1, is such that the upper end thereof will be disposed closely adjacent the closed end of.

the cylinder.

When the highly heated cylinder is immersed in the bath, as hereinbefore pointed out, the cooling fluid will be forced into the cylinder and distributed throughout the same through the plurality of openings 19 in the feed-pipe 16. The fluid in cooling the cylinderwill become heated and the hot fluid will pass from. the cylinder through the openings 22 andthrough the open bottom thereof. the hot fluid passes into the adjacent portion of the bath, the same will rise to the top and be skimmed 011' through the flow of the fluid over the dam 13.

The vent openings 22 at the closed end of the cylinder are important in carrying out my improved process, because if such openings are not provided the cooling fluid which becomes heated will be trapped in the cylinder, thus preventing proper circulation of the fluid and interfering with the rapid cooling of the cylinder. In fact, due to the extreme Ey high temperature of the cast cylinder which is immersed in the bath, the cooling fluid at the closed end of the cylinder would be converted into steam'unless such vent openings are provided.

From the preceding description, taken in connection with the drawing, it will be evident that I have provided a simple and efficient apparatus and process for quenching steel castings and the like, wherein the temperature of the cooling bath is'kept at a minimum, thereby effecting rapid cooling of the article being quenched, thusgreatly increasing the capacity of the apparatus and eifecting a substantial economy in the time consumed and increasing the output.

While I have herein shown and described what I consider the preferred manner of can rying out my invention, the same is merely illustrative and I contemplate all changes and modifications which come within the scope of the claims appended hereto.

I claim: I

1. In a process of quenching cylindrical articles open at one end and having vent openings adjacent the closed end; immersing said article in the bath while in inverted condition; and feeding a cooling fluid to said bath and forcing the same into the interior of said cylinder through the open bottom thereof and causing a circulation of said fluid through said cylinder and the vent openings thereof.

2. In a process of quenching a tubular article open at one end and having vent openings adjacent the closed end;'immersing said tubular article in a cooling bath in inverted condition; supporting said article so as to permit an unobstructed flow of cooling fluid from the open end thereof; forcing a cooling fluid into said tubular member through the the same into said cylinder through the open end thereof.

4. In a quenching bath arrangement for a tubular article closed at one end, the combination with a tank adapted to contain a coolin fluid; of means for draining the cooling fluid from the top of the bath; means for supporting said tubular article with the open end portion at the bottom and spaced from the bottom wall of the tank; means for feeding a coolingfluid to said tank, including an inlet pipe extending into said tubular article for forcing the cooling fluid through the same.

5. In a quenching bath'arrangement for a cylindrical article closed at one end, the combination with a tank adapted to contain a cooling fluid; of means for supporting said cylinder in the tank in inverted condition with the open end thereof spaced from the bottom of said tank; and means for feeding a cooling fluid into said tank, including a pipe extending vertically into said cylinder through the open end and terminating adjacent the closed endthereof, said pipe having a plurality of openings in the side wall for distributing the cooling fluid throughout the height of said cylinder.

In witness that I claim the foregoing I have hereunto subscribed my name this 7th day of January 1929.

GEORGE A. JOHNSON.

open bottom end thereof and causing said fluid to circulate through said cylinder and pass from the same through said vent openings and the open end thereof.

3. In a quenching bath arrangement for a cylindrical article open at one end, the combination with a tankadapted to contain a cooling fluid in which said cylindrical article is quenched; of a removable carrier for said cylinder, supporting the latter in inverted condition in said bath in spaced relation to the bottom of said tank; and means for feed- 5 mg cooling fluid to said bath and forcing 

